Patent GB-189919189-A (GB)
Title: Means and Apparatus for Electrically Working Vacuum and Air Pressure Railway Brakes.
Filed: 1899-09-23
Granted: 1900-09-22
Abstract: 19,189. Siemens Bros. & Co. [Siemens & Halske Aktiengesellschaft]. Sept. 23. Brakes.-Relates to pneumatic brakes for electrically-propelled trains. When the handle h, Fig. 1, is removed, the electric switch s is kept in the open position I-I by the spring f and the driver's valve K is maintained by the spring f<1> in the position II-II, which in automatic vacuum brakes corresponds to " running" and in compressed-air brakes to "charging " or "releasing." On placing the handle h on the extremity y of the switch s, which is loose on the stud C, the pins b prevent it from descending below the edges of the guide-plates sch. As the switch is moved from the position I-I to the position II-II the electric circuit is closed through a resistance wa, and the electricallydriven air pump LM is started. In the position II-II, the finger F can enter the radial slot z, and be pressed into the notch r in the valve K. The parts s and K can now be moved together, and at M-M the pump is stopped, and in the case of a vacuum brake the train-pipe is just opening to admit air. Braking is now effected by turning the valve slowly or rapidly to the extreme or emergency position I-I. The handle h cannot be removed until it is returned to the position II-II, when the pump is at work and the brakes are "off." In trains with several motor carriages having similar brake apparatus, the switch connection on the leading carriage is modified. As the finger F is being depressed to fit into the notch r, it strikes the arm u of the spring lever kh, causing it to swing the switch G into the position shown in dotted lines, thereby closing a circuit in which the regulating-resistance R for the pump of the first carriage is included. As the pins b traverse the slots t of the guides sch the arm u is freed, and when the handle h is removed it knocks back the arm u and brings the switch G into its original position. An automatic connecting and disconnecting switch aa for the air-pump motor, emergency switch N, pressure-regulating valve dv, and an emergency contact on the brake valve, are fitted. In trains drawn by an electric locomotive with air-pressure brakes, an electric lead passes along the train, and is provided on each carriage with a switch united to and movable with the cock of the train-pipe, and on the last carriage with a special switch generally worked by hand. Trains with motor carriages and airpressure brakes have two train-pipes fitted with corresponding leads and switches. Fig. 9 shows means for working the brakes by the ordinary controller handle K, which, when fitted in the position 2, Fig. 8, causes the finger f to engage in the notch e of the disc S attached to the toothed sector az<1> loose on the controller shaft c, and at the same time to depress the hook h turning the switch G and with it the valve H. As the handle is turned to the position I, the sectors az<1>, az<2> rotate the shaft aw and the starting-switch as for the pump motor: When the notch E is over the projection a, the handle F can be depressed until the hole nv engages with the square v formed on the controller shaft. Should the driver release the crank K in the position I, the weight Q draws it into the position 2. In this motion the sectors az<1>, bz<1> gear with the sectors az<2>, bz<2>, (A) causing the switch as to start the pump motor, and (B) bringing the cock BH, loose on the shaft aw and connected to the sector bz<2> by the pawl and ratchet coupling ks, into the braking position. The sectors, which remain out of gear as the handle passes from I to IV, Fig. 8, may be replaced by cams. An emergency key ns is used to bring the brake valve BH into any position by means of the ratchet connection ks without altering the relative positions of the other devices. Should the key ns be left in an incorrect position, the guard kr<2> will act as a stop which the guard kr<1> will strike on returning the controller handle and ensure the correct gearing of the sectors.